Pushing the limits of Full-duplex: Design and Real-time Implementation

By Achaleshwar Sahai, Gaurav Patel, Ashutosh Sabharwal. arXiv.org, 2011

334 citations recorded by the source corpus.

Recent work has shown the feasibility of single-channel full-duplex wireless physical layer, allowing nodes to send and receive in the same frequency band at the same time. In this report, we first design and implement a real-time 64-subcarrier 10 MHz full-duplex OFDM physical layer, FD-PHY. The proposed FD-PHY not only allows synchronous full-duplex transmissions but also selective asynchronous full-duplex modes. Further, we show that in over-the-air experiments using optimal antenna placement on actual devices, the self-interference can be suppressed upto 80dB, which is 10dB more than prior reported results. Then we propose a full-duplex MAC protocol, FD-MAC, which builds on IEEE 802.11 with three new mechanisms -- shared random backoff, header snooping and virtual backoffs. The new mechanisms allow FD-MAC to discover and exploit full-duplex opportunities in a distributed manner. Our over-the-air tests show over 70% throughput gains from using full-duplex over half-duplex in realistically used cases.

Subfields: Computer Networks and Communications, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/141eb580818b754466b6ab55f9bce29f9370dda5

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In Computer Networks and Communications

In Electrical and Electronic Engineering

Citations in the corpus

Experiment-Driven Characterization of Full-Duplex Wireless Systems (2011, methodology): “width of 10 0.625 MHz (128 samples per symbol). Our self-interference cancellation can be extended to wideband (e.g. 802.11g) by applying the proposed cancellation schemes per subcarrier, as shown in [13]. Transmitted QPSK symbols were shaped using a squared root raised cosine pulse shaping ﬁlter wi”
Full-Duplex Transceiver System Calculations: Analysis of ADC and Linearity Challenges (2014, methodology): “the PA nonlinearity perspective, Case B is equivalent to the method used in [5] and [29], where a separate low-power TX chain is used to generate the RF reference signal.”
A Survey of In-Band Full-Duplex Transmission: From the Perspective of PHY and MAC Layers (2015, background): “back-off, snooping to discover IBFD transmission opportunity, and virtual contention resolution [33].”
Passive Self-Interference Suppression for Full-Duplex Infrastructure Nodes (2013, methodology): “For active self-interference cancellation, we adopted the persubcarrier analog and digital cancellation mechanisms demonstrated in [7], [11], [28].”
Full-Duplex Wireless Communications: Challenges, Solutions, and Future Research Directions (2016, methodology): “Explicitly, the BER associated with dirty estimation may become a factor six higher compared to that of clean estimation [15].”
In-Band Full-Duplex Technology: Techniques and Systems Survey (2019, background): “tion and analog domains [131]–[154], while three focused on”
Widely Linear Digital Self-Interference Cancellation in Direct-Conversion Full-Duplex Transceiver (2014, background): “To suppress such SI inside the transceiver, various antenna-based solutions [2], [4], [12], [13], active analog/RF cancellation methods [2]– [4], [8], [14]–[16] and digital baseband cancellation techniques [3], [14], [17], [18] have been proposed in the literature.”
Full duplex techniques for 5G networks: self-interference cancellation, protocol design, and relay selection (2015, methodology): “Mechanisms of FD-MAC protocol [4] — shared random backoff (SRB), snooping, and virtual contention resolution — can be employed for addressing the problem of the hidden terminal.”
In-Band Full-Duplex Wireless: Challenges and Opportunities (2013, methodology): “Scanning the literature on self-interference cancellation, we observe that the proposed techniques use a combination of wireless-propagation-domain techniques [2]–[6], [11]–[41], analog-circuit-domain techniques [2], [13], [24], [25], [28], [29], [31], [42]–[48] and/or digital-domain techniques [2],”
Optimal Resource Allocation in Full-Duplex Wireless-Powered Communication Network (2014, background): “9 shows the average sum-rates of FD- and HD-WPCNs over the number of users, K, for different values (6)By current techniques, it has been reported that SI can be canceled up to −81dB in analog domain [23].”
In-Band Full-Duplex Relaying: A Survey, Research Issues and Challenges (2015, background): “For example, the authors of [7], [8], [11], [15], [68], [71] preliminarily demonstrate the feasibility of bidirectional communications for the networks (e.”